The first polar bear cub born in the UK for 25 years has finally ventured outside.

The cub was born in the week before Christmas but had only been confirmed by high-pitched noises heard from the maternity den at the Royal Zoological Society of Scotland’s (RZSS) Highland Wildlife Park, near Kingussie.

The first pictures of the cub have now been released after it was caught on camera sitting in the snow for an upcoming Channel 4 documentary about the park’s pioneering polar bear breeding programme.

It is still not known if the unnamed cub is a boy or a girl and it has been closely guarded by mother Victoria, who mated with Arktos, one of two male polar bears at the park.

The charity described the birth as an “outstanding achievement” but stressed that the first three months can be perilous for polar bear cubs, both in the wild and in captivity.

Victoria and her cub’s enclosure will remain closed to the public until late March.

Una Richardson, head keeper responsible for carnivores, said: “Victoria had started to come outside by herself for short periods to eat, drink and roll around in the snow, so we knew her cub would soon follow her but we couldn’t be sure when.

“I was visiting Victoria on Sunday morning to check she had fresh water and to continue slowly reintroducing food to her diet, after four months during which she lived solely off the fat reserves she built up before she entered her den.

“Suddenly I saw a small, fluffy bundle next to her and had to pinch myself to check I wasn’t seeing things. It was a very special experience and one I’ll never forget.

“We also have motion-sensitive cameras safely positioned near Victoria’s den and we were delighted to see we had captured her cub’s first few steps outside.

“Having only been able to hear sounds from inside the den before, we can now be certain Victoria has had one cub rather than two and we couldn’t be happier as this is the moment we have been working towards and really looking forward to.”

Both bears are said to be doing well and keepers will decide on a name after confirming the sex of the cub in the coming weeks.

Newborn polar bear cubs only open their eyes when they are a month old and are entirely dependent on their mother, feeding on fat-rich milk to grow quickly, weighing around 10kg to 12kg by the time they leave their den.

Douglas Richardson, head of living collections at the park, said staff were “thrilled” by the cub’s progress.

“Some may wonder whether there is any point in breeding polar bears in zoos and the question deserves a serious answer,” Mr Richardson said.

“The change in the Arctic climate, specifically the shortening of the ice season, coupled with more direct human pressures, is having a noticeably detrimental effect on the species that is likely to result in many of the wild sub-populations disappearing.

“If we do not develop and maintain a genetically and behaviourally robust captive polar bear population, we will not have the option, should we require it, to use them to support what is likely to be a diminished and fragmented wild population in the future.”

The documentary, Britain’s Polar Bear Cub, is to air on Channel 4 on Sunday March 18.

Krista Wright, executive director of conservation charity Polar Bears International, said: “With polar bears facing grave threats from sea ice loss in a warming climate, it is important for facilities like Highland Wildlife Park to help educate visitors and involve them in solutions.

“This cub will serve as an ambassador for its wild cousins, inspiring people to care.”